Hi, bytesleft == 0 means no more data in this frame. bytesleft == 0 and CURLWS_CONT bit is not set means the end of the message.
-- Mike ср, 12 июл. 2023 г. в 13:00, <curl-library-requ...@lists.haxx.se>: > Send curl-library mailing list submissions to > curl-library@lists.haxx.se > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.haxx.se/mailman/listinfo/curl-library > or, via email, send a message with subject or body 'help' to > curl-library-requ...@lists.haxx.se > > You can reach the person managing the list at > curl-library-ow...@lists.haxx.se > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of curl-library digest..." > > > Today's Topics: > > 1. Detecting final WebSocket frame of a fragmented message > (Paul Fotheringham) > 2. RE: Detecting final WebSocket frame of a fragmented message > (Dmitry Karpov) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Tue, 11 Jul 2023 17:35:19 +0100 > From: Paul Fotheringham <fotheringham.p...@gmail.com> > To: curl-library@lists.haxx.se > Subject: Detecting final WebSocket frame of a fragmented message > Message-ID: > <CAGThwFanQ_A6MCmekV-f7tVCM= > s2yg2cmdqhvirr41rz8gq...@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > Hi, > > I've been using libcurl for some months now and recently tried to get > WebSocket going in CURLOPT_CONNECT_ONLY=2L mode. The problem I'm > having is if the server sends a message fragmented over multiple > frames then I cannot work out how I am meant to know when the final > frame of the message is received via curl_ws_recv. Even if it is not > fragmented then I get the whole message but again I guess I don't know > that the message is finished. > > My understanding of WebSocket is that only the final frame (might be > the only frame) has the FIN bit set in the header but I see no > corresponding exposure of that in the API and a quick scan of the code > seems to suggest it is not being passed out in any way. The server is > mine too so I may have a bug but at the same time I just don't see how > I'm meant to detect the final frame. > > I understand WebSocket support is still experimental so I'm wondering > if I am missing something or if this is just not available yet? > > Paul > > > ------------------------------ > > Message: 2 > Date: Tue, 11 Jul 2023 18:26:58 +0000 > From: Dmitry Karpov <dkar...@roku.com> > To: libcurl development <curl-library@lists.haxx.se> > Subject: RE: Detecting final WebSocket frame of a fragmented message > Message-ID: > < > byapr01mb5606ba7686ffc06c11b75a3fc3...@byapr01mb5606.prod.exchangelabs.com > > > > Content-Type: text/plain; charset="us-ascii" > > I guess the "offset" and "bytesleft" in the curl_ws_meta structure ( > https://curl.se/libcurl/c/curl_ws_meta.html) > provide information about WS message fragments. > > "offset" > When this frame is a continuation of fragment data already delivered, this > is the offset into the final fragment where this piece belongs. > > "bytesleft" > If this is not a complete fragment, the bytesleft field informs about how > many additional bytes are expected to arrive before this fragment is > complete. > > I suppose that for the final frame in the WS message the "bytesleft" field > should be set to zero thus indicating the end of the message. > > Thanks, > Dmitry Karpov > > > > -----Original Message----- > From: curl-library <curl-library-boun...@lists.haxx.se> On Behalf Of Paul > Fotheringham via curl-library > Sent: Tuesday, July 11, 2023 9:35 AM > To: curl-library@lists.haxx.se > Cc: Paul Fotheringham <fotheringham.p...@gmail.com> > Subject: [EXTERNAL] Detecting final WebSocket frame of a fragmented message > > Hi, > > I've been using libcurl for some months now and recently tried to get > WebSocket going in CURLOPT_CONNECT_ONLY=2L mode. The problem I'm having is > if the server sends a message fragmented over multiple frames then I cannot > work out how I am meant to know when the final frame of the message is > received via curl_ws_recv. Even if it is not fragmented then I get the > whole message but again I guess I don't know that the message is finished. > > My understanding of WebSocket is that only the final frame (might be the > only frame) has the FIN bit set in the header but I see no corresponding > exposure of that in the API and a quick scan of the code seems to suggest > it is not being passed out in any way. The server is mine too so I may have > a bug but at the same time I just don't see how I'm meant to detect the > final frame. > > I understand WebSocket support is still experimental so I'm wondering if I > am missing something or if this is just not available yet? > > Paul > -- > Unsubscribe: https://lists.haxx.se/mailman/listinfo/curl-library > Etiquette: https://curl.se/mail/etiquette.html > > > ------------------------------ > > Subject: Digest Footer > > -- > Unsubscribe: https://lists.haxx.se/mailman/listinfo/curl-library > Etiquette: https://curl.haxx.se/mail/etiquette.html > > > ------------------------------ > > End of curl-library Digest, Vol 24, Issue 4 > ******************************************* >
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